System Information
Operating system: Windows
Graphics card: GeForce 1080Ti

Blender Version
Broken: version: 2.80 (sub 75), branch: master, commit date: 2019-07-29 14:47, hash: f6cb5f54494e,
build date: 2019-07-29, 09:44 AM

Short description of error
Simplify F-Curves seem not to work with very tiny objects.

Exact steps for others to reproduce the error

I've a small medaillon, that is just 10 centimeters wide. There is a small animated bird inside.
Simplify F-Curves doesn't work, even when I set an error value of "0.00001".
The result: The curves are completely cleaned and became nearly straight lines after simplifying them.

Note: All works fine with big sized objects in meters. So there seem to be a problem with the decimal places value.

I've verified this issue in the following situation:
I've scaled my object 10 times as big, and the Addon worked then.
So please correct this great tool to use it with very tiny models too.
Animation curves can't be scaled proportionally, while objects are scaled as I know.

Thank you

@Philipp Oeser (lichtwerk)